Transceiver arrangement, communication device, method and computer program

Abstract

A transceiver arrangement comprises a receiver arranged for frequency-division duplex communication with a communication network; a transmitter arranged for frequency-division duplex communication with the communication network; a transmission port for connecting to an antenna or wire; a first filter connected between an output of the transmitter and the transmission port and arranged to pass signals at transmitter frequency and attenuate signals at receiver frequency; a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port; a second filter connected between another of the terminals of the primary winding and a reference voltage and arranged to attenuate signals at transmitter frequency and pass signals at receiver frequency; and an adaptive impedance circuit arranged to provide an adjustable resistance, connected between the output of the transmitter and the junction between the second filter and the another of the terminals of the primary winding, and arranged to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at receive frequency. A communication device, a method of controlling a transceiver arrangement, and a computer program are also disclosed.

The invention claimed is: 
     
       1. A transceiver arrangement, comprising:
 a receiver configured for frequency-division duplex communication with a communication network; 
 a transmitter configured for frequency-division duplex communication with the communication network; 
 a transmission port for connecting to an antenna or wire; 
 a first filter connected between an output of the transmitter and the transmission port, the first filter configured to pass signals at a transmitter frequency and attenuate signals at a receiver frequency; 
 a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port; 
 a second filter connected between another of the terminals of the primary winding and a reference voltage, the second filter configured to attenuate signals at the transmitter frequency and pass signals at the receiver frequency; 
 an adaptive impedance circuit configured to provide an adjustable resistance, the adaptive impedance circuit connected between the output of the transmitter and a junction between the second filter and the another of the terminals of the primary winding, the adaptive impedance circuit configured to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at the receive frequency. 
 
     
     
       2. The transceiver arrangement of  claim 1 , further comprising a third filter connected between the output of the transmitter and a reference voltage, the third filter configured to attenuate signals at the transmitter frequency and pass signals at an interferer frequency. 
     
     
       3. The transceiver arrangement of  claim 1 , further comprising a fourth filter connected at the input of the receiver, the fourth filter configured to attenuate signals at the receive frequency and pass signals at an interferer frequency. 
     
     
       4. The transceiver arrangement of  claim 3 , wherein the fourth filter is connected across differential input terminals of the receiver. 
     
     
       5. The transceiver arrangement of  claim 3 , wherein the fourth filter is connected between a single-ended input terminal of the receiver and a reference voltage. 
     
     
       6. The transceiver arrangement of  claim 1 :
 wherein the first filter comprises a capacitance and a first inductance coupled in parallel, wherein the parallel coupling of the first filter is coupled in series with a second inductance; 
 wherein the second filter comprises a first capacitance and an inductance coupled in parallel, wherein the parallel coupling of the second filter is coupled in series with a second capacitance. 
 
     
     
       7. The transceiver arrangement of  claim 6 :
 wherein at least one of the capacitance and the first and second inductances of the first filter is controllable and is controlled by a controller; 
 wherein at least one of the inductance and the first and second capacitances of the second filter is controllable and is controlled by the controller. 
 
     
     
       8. The transceiver arrangement of  claim 7 , wherein the first filter comprises a further capacitance coupled in series with the second inductance, and the further capacitance is controllable and is controlled by the controller. 
     
     
       9. The transceiver arrangement of  claim 8 :
 wherein at least one of the inductance and the first and second capacitances of the first filter is controllable and is controlled by a controller; 
 wherein at least one of the capacitance and the first and second inductances of the second filter is controllable and is controlled by the controller. 
 
     
     
       10. The transceiver arrangement of  claim 9 , wherein the second filter comprises a further capacitance coupled in series with the second inductance, and the further capacitance is controllable and is controlled by the controller. 
     
     
       11. The transceiver arrangement of  claim 1 :
 wherein the first filter comprises a first capacitance and an inductance coupled in parallel, wherein the parallel coupling of the first filter is coupled in series with a second capacitance; 
 wherein the second filter comprises a capacitance and a first inductance coupled in parallel, wherein the parallel coupling of the second filter is coupled in series with a second inductance. 
 
     
     
       12. The transceiver arrangement of  claim 1 :
 further comprising a signal detector arrangement at a terminal or terminals of an input port of the receiver or at the terminals of the primary winding; 
 further comprising a controller configured to control at least one of the first filter, the second filter, and the adaptive impedance circuit based on detected signal or signals from the signal detector such that the transmitter contribution at the receiver input at receive frequency is minimized. 
 
     
     
       13. A communication device, capable of frequency division duplex communication via a communication network, comprising:
 a transceiver arrangement; 
 wherein the transceiver arrangement comprises:
 a receiver configured for frequency-division duplex communication with the communication network; 
 a transmitter configured for frequency-division duplex communication with the communication network; 
 a transmission port for connecting to an antenna or wire; 
 a first filter connected between an output of the transmitter and the transmission port, the first filter configured to pass signals at a transmitter frequency and attenuate signals at a receiver frequency; 
 a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port; 
 a second filter connected between another of the terminals of the primary winding and a reference voltage, the second filter configured to attenuate signals at the transmitter frequency and pass signals at the receiver frequency; 
 an adaptive impedance circuit configured to provide an adjustable resistance, the adaptive impedance circuit connected between the output of the transmitter and a junction between the second filter and the another of the terminals of the primary winding, the adaptive impedance circuit configured to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at the receive frequency. 
 
 
     
     
       14. A method of controlling a transceiver arrangement; the transceiver arrangement comprising a receiver and a transmitter configured for frequency-division duplex communication with a communication network, a transmission port for connecting to an antenna or wire, a first filter connected between an output of the transmitter and the transmission port, the first filter configured to pass signals at a transmitter frequency and attenuate signals at a receiver frequency, a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port, a second filter connected between another of the terminals of the primary winding and a reference voltage, the second filter configured to attenuate signals at the transmitter frequency and pass signals at the receiver frequency, and an adaptive impedance circuit configured to provide an adjustable resistance, the adaptive impedance circuit connected between the output of the transmitter and a junction between the second filter and the another of the terminals of the primary winding, the adaptive impedance circuit configured to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at receive frequency; wherein the method comprises:
 setting filter parameters such that:
 the first filter passes signals at the transmitter frequency and attenuates signals at the receiver frequency; and 
 the second filter attenuates signals at the transmitter frequency and passes signals at the receive frequency; 
 
 adjusting the adjustable resistance of the adaptive impedance circuit such that magnitude of transmitter contribution in the primary winding is reduced; and 
 phase tuning at least one impedance element of at least one of the first filter, the second filter, and the adaptive impedance circuit, such that an amplitude is minimized. 
 
     
     
       15. The method of  claim 14 :
 further comprising measuring signals at the receiver input or at the primary winding of the transformer; 
 wherein at least one of the following is based on the measured signals:
 the adjusting of the adjustable resistance; 
 the phase tuning. 
 
 
     
     
       16. A computer program product stored in a non-transitory computer readable medium for controlling a transceiver arrangement; the transceiver arrangement comprising a receiver and a transmitter configured for frequency-division duplex communication with a communication network, a transmission port for connecting to an antenna or wire, a first filter connected between an output of the transmitter and the transmission port, the first filter configured to pass signals at a transmitter frequency and attenuate signals at a receiver frequency, a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port, a second filter connected between another of the terminals of the primary winding and a reference voltage, the second filter configured to attenuate signals at the transmitter frequency and pass signals at the receiver frequency, and an adaptive impedance circuit configured to provide an adjustable resistance, the adaptive impedance circuit connected between the output of the transmitter and a junction between the second filter and the another of the terminals of the primary winding, the adaptive impedance circuit configured to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at receive frequency; the computer program product comprising software instructions which, when run on a processing circuit of the a processing circuit of a transceiver arrangement, causes the processing circuit to:
 set filter parameters such that:
 the first filter passes signals at the transmitter frequency and attenuates signals at the receiver frequency; and 
 the second filter attenuates signals at the transmitter frequency and passes signals at the receive frequency; 
 
 adjust the adjustable resistance of the adaptive impedance circuit such that magnitude of transmitter contribution in the primary winding is reduced; and 
 phase tune at least one impedance element of at least one of the first filter, the second filter, and the adaptive impedance circuit, such that an amplitude is minimized.